| # | Point | LinkedList | ArrayList |
|---|---|---|---|
| 1 | Nature | LinkedList is Sequential Access | ArrayList is Random Access |
| 2 | Internal Implementation | LinkedList is implemented by Doubly-linked list | ArrayList is implemented by Array |
| 3 | get(index) complexity | LinkedList is of O(n), needs to iterate over elements | ArrayList is of O(1), direct access |
| 4 | add(element) complexity | LinkedList is O(1), always has pointer to last element, just add a new node | ArrayList is O(1) * O(n) in worst-case if array capacity reached to modCount and array needs to be resized and copied |
| 5 | add(index,element) complexity | LinkedList is of O(n), need to iterate till nth element | ArrayList is of O(n-index), (n-index) element needs to be shifted * O(n) in worst-case if array capacity reached to modCount and array needs to be resized and copied |
| 6 | ListIterator.add(element) complexity | LinkedList is of O(1), only pointers needs to be adjusted | ArrayList is of O(n-index), (n-index) element needs to be shifted * O(n) in worst-case if array capacity reached to modCount and array needs to be resized and copied |
| 7 | remove(index) complexity | O(n), need to iterate to reach nth element | O(n-index), (n-index) element needs to be shifted |
| 8 | ListIterator.remove(element) complexity | O(1), only pointers needs to be adjusted | O(n-index), (n-index) element needs to be shifted * O(n) in worst-case if array capacity reached to modCount and array needs to be resized and copied |
| 9 | Memory usages | More, previous and next pointers to be maintained | Less |